Atmospheric fired boiler



June 4, 1968 Filed May 19, 1966 FIGI J. C. CLEAVER ET AL ATMOSPHERIC FIRED BOILER 2 Sheets-Sheet 1 |NVENTORS JOHN- C. CLEAVER GUSTAV A. REHM GLENN D.CRA|G WALTER J. BARON FRANK GETHING BY FRED s. WIEGRATZ g w '46", JWE 721. (ml- ATTORNEYS June 4, 1968 J. c. CLEAVER ET AL 3,386,420

ATMOSPHERIC FIRED BOILER Filed May 19, 1966 2 Sheets-Sheet 2,

FIGB FlG.4

United States Patent ATMOSPHERIC FIRED BOILER John C. Cleaver, River Hills, Gustav A. Rehm, Milwaukee, Glenn D. Craig, Menomonee Falls, Walter J. Baron, Hubertus, Frank Gething, Shorewood, and Fred G. Wiegratz, New Berlin, Wis., assignors to Cleaner- Brooks Company, a corporation of Wisconsin Filed May 19, 1966, Ser. No. 551,361

12 Claims. (Cl. 122-235) ABSTRACT OF THE DISCLOSURE An atmospheric fired boiler including a cold water inlet drum and a hot water-steam outlet drum, with a plurality of heat exchange panels extending between the cold water inlet drum and the hot water-steam outlet drum. Each panel includes a plurality of vertically spaced connecting members extending between an inlet header that communicates with the cold water inlet drum and an outlet header that communicates with the hot waterseam outlet drum. Each connecting member includes generally horizontally disposed outer end portions, and an upwardly inclined intermediate portion.

This invention relates in general to an improved atmospheric fired boiler, and more particularly to an atmospheric fired boiler construction which may be used as a hot water boiler or a steam boiler.

In the prior art, many problems have been experienced by boiler designers in providing a consistent circular pattern throughout the boiler. Very often the circular pattern would change in response to changing loads on the boiler, so that water would be moving upwardly at one firing rate of the boiler, downwardly at another firing rate, and standing still at a still further firing rate. The present invention obviates this problem by providing a unique riser and downcomer arrangement which produces a continuous, unimpeded circulation pattern, and wherein all heated surfaces carrying water going up, while unheated surfaces carrying water coming down.

In known types of watertube steam generating boilers, it has been necessary to provide complex and costly steam separators to prevent water from carrying over into the steam line. The novel downcomer and riser panel structure of the present invention and the unchanging circulation pattern resulting therefrom completely eliminates the necessity of providing steam separators. Prior art atmospheric fired boilers have also been relatively time consuming and difficult to fabricate, and thus have been relatively high in cost. Accordingly, the general purpose of the present invention is to provide an improved and simplified atmospheric fired boiler construction, which is relatively inexpensive to manufacture, and which has operating characteristics which exceed those of known devices.

An object of the invention is to provide an atmospheric fired boiler with a plurality of heat exchange panels or risers formed of tubular members.

Another object of the invention is to provide an atmospheric fired boiler with a novel riser construction having an expanded heat transfer surface to enhance the heat exchange between the flue gases and the water passing through riser structure.

A further object of the invention is to arrange the tubular members of riser structure as described above in such a manner as to provide a tortuous path for the flue gases.

Still another object of the invention is to arrange the riser members of an atmospheric fired boiler in a manner 3,386,420 Patented June 4, 1968 ice such as to provide water cooling at the ends .of the bottom of the boiler.

Yet another object of the invention is to provide riser members as described above with the means for positively directing water from an inlet drum to a hot water-steam outlet drum.

A still further object of the invention is to provide an atmospheric fired boiler as described above with a novel downcomer arrangement, wherein the downcomer means is spaced from the heating area of the boiler.

These and other objects of the invention will become more fully apparent from the following specification, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a front perspective view of a preferred embodiment of the invention;

FIG. 2 is a front perspective view of the embodiment of FIG. 1, with the housing removed;

FIG. 3 is a fragmentary side elevational view of the embodiment illustrated in FIG. 1, with certain parts broken away from clarity of illustration;

FIG. 4 is a sectional view taken generally along line 4-4 of FIG. 3 with the refractory material removed to more clearly illustrate the end riser panel structure;

FIG. 5 is a sectional view taken generally along line 5 -5 of FIG. 3, with certain parts broken away to clearly illustrate the intermediate riser panel structure;

FIG. 6 is an enlarged, fragmentary sectional view taken generally along line 6-6 of FIG. 3; and

FIG. 7 is a central sectional view through a riser, showing the junction between one of the vertically extending headers and one of the generally horizontally extending connecting members.

While this invention is susceptible of embodiment in many different forms, the is shown in the dawings and will herein be described in detail a preferred embodiment of the invention with the understanding that the present disclosure is to be considered as an exemplificaton of the principles of the invention as is not intended to limit the invention to the embodiment illustrated. The scope of the invention will be pointed out in the appended claims.

Referring to the drawings in greater detail, a steam generating atmospheric fired boiler is shown generally at 10, and includes a housing 11 having a front wall 12, side walls 13, and rear wall 14. Boiler 10 is supported on a base B extending longitudinally of the boiler between housing front and rear walls 12 and 14. Heating means 15 is provided at the lower portion of the housing 11 (FIGS. 3-5), and a plurality of longitudinally space-d heat exchange panels or risers 16, 116 and 216 extend between housing walls 12-14, and are connected between a cool water inlet drum 17 at the lower portion of the housing and steam outlet drum 18 at the upper portion of the housing. Lower drum 17 is supported on base B, and is preferably secured to the lower portion of housing front and rear walls 12 and 14, while the upper drum 18 is supported by the risers with the outer ends of upper drum 18 being positioned in enlarged extensions 12a and 14a in the housing front and rear walls, respectively. One or more steam outlets 18 is provided in upper drum 18.

As can be best seen in FIG. 5, intermediate panels 16 each include a generally vertically extending inlet header 19 and a generally vertically extending outlet header 20. Durms 17 and 18 are tubular cylindrical members, and drum 17 includes a plurality of longitudinally spaced openings 17a and 17b in opposite sides thereof, while drum 18 is provided with a plurality of longitudinally spaced holes 18a and 18b in opposite sides thereof. Holes 17a and 18a are longitudinally offset from holes 1711 and 18b, and holes 17a and 18b are positioned in a common vertical plane, while holes 17b and 18a are also posi- 3 tioned in a common vertical plane, as will hereinafter appear. Sealing plates are bolted, or otherwise suitably secured, to opposite ends of drums 17 and 18.

The inlet headers 19 of each panel 16 are positioned on one side of drums 17 and 18, while the outlet headers 20 are positioned on the opposite side of drums 17 and 18. Each inlet header 19 includes a laterally extending, horizontally disposing lower portion 19a which communicates with drum 17 through opening 17a, while each outlet header 20 includes a laterally extending upper portion 20a which communicates with drum 18 through opening 18a. Header portions 19a and 20a are preferably secured to drums 17 and 18 around openings 17a and 18b, respectively, by welding. The inlet headers 19 and outlet headers 20 are each provided with a plurality of vertically spaced openings 21, which are identical with that shown in FIG. 7. As shown therein, a peripheral flange 22 extends outwardly from the generally vertically disposed header portion 19, at right angles with respect thereto. The flanges 22 around the openings 21 are preferably fabricated by first forming an elliptical opening in the header wall, and then drawing a semi-spherical object through the opening. This provides rounded corners 21a at the junction between the header 19 and the flange 22, which minimizes the entrance losses of water flowing outwardly of the header through the openings 21.

As can be clearly seen in FIG. 5, the upper end of inlet header 19 terminates at 23 a substantial distance below steam drum 18, while the lower end 24 of outlet header 20 is positioned a slight distance above the lowermost opening in the inlet header 19. Suitable closure members are secured, as by welding, to the header end portions 23 and 24. A plurality of generally transversely extending connecting members 25 extend between corresponding openings in the inlet header 19 and the outlet header 20 to provide an expanded heat exchange area. Connecting members 25 each include an upwardly extending central portion 25c with generally horizontally extending portions 25a and 2512 at the outer ends thereof. The end portions 25a and 25b of connecting members 25 are positioned in alignment with the flanges 22 on headers 19 and 20 respectively, and are secured thereto as by welding at 26. An annular back up ring 27 extends partially into each flange 22, and into the adjacent end portion of the connecting member 25 to reinforce welded connection 26.

Adjacent intermediate heat exchange riser panels are reversed throughout the length of the boiler, and the effect of this arrangement can be best visualized from FIGS. 2 and 5, where corresponding elements of the riser adjacent to riser 16 have been increased by the sum 100. With this arrangement, the lower portions 119a of the inlet headers 119 communicate with the openings 17b inlet drum 17, while the upper portions 120a of the outlet risers 120 communicate with the openings 18av in steam drum 18. The inclined portions 125c of connecting members 125 are inclined upwardly in an opposite direction from the inclined portions 25c of connecting members 25, and the inclined portions 250 and 1250 cooperate to effectively define a tortuous flow path for the flue gases emanating from the heating means 15. The vertical headers 19, 20, 119 and 120 define a heat exchange space which is generally rectangularly in cross section, and the connecting members 25 and 125 are spaced a substantial distance above the heating means to define a combustion chamber C therebelow.

In the illustrated embodiment, the heating means 15 includes a plurality of longitudinally and transversely spaced gas burning nozzles 28, which are connected to a suitable gas supply by manifold lines 29. Nozzles 28 are preferably of the type disclosed in the copending application of Stiefel, Ser. No. 351,804, filed Mar. 13, 1964, and having the same assignee as the present application. As is clear from FIG. 5, nozzles 28 extend upwardly above the lower header portions 19:: and 119a into the combustion chamber C. Air for combustion is drawn into the combustion chamber C through louvers 30 in the lower portion of the side walls 13 of the boiler housing. The flue gases, resulting from the gas combustion within combustion chamber C, flow upwardly around the expanded heat exchange area provided by connecting members 25 and 125. The flue gases contact the connecting members 25 and 125 on both sides thereof, and flow in and around the tubes through the tortuous path created by the crossing inclined portions 250 and 1250 to heat and evaporate the water flowing upwardly in the risers. Since the nozzles 28 are positioned above the lower horizontally disposed header portions 19a and 119a, the bottom of the boiler is water cooled by Water flowing into the header portions 19a and 119a from the inlet drum 17.

The endmost riser panels are similar to the intermediate riser panels 16, and accordingly, similar reference numerals have been utilized to indicate corresponding elements, and have been increased by the sum 200. End panels 216 include generally vertically disposed inlet headers 219 having generally horizontally disposed lower portions 219a communicating with water inlet drum 17, and also include outlet headers 220 having laterally extending upper portions 220a communicating with steam drum 18. Connecting members 225, having upwardly inclined central portions 225e, extend between corresponding openings in the inlet headers 219 and 220, and horizontal portions 225a and 225b at opposite ends of members 225 are secured to flanges 222 surrounding the header openings. Panels 216 differ from panels 16 and 116 primarily in the number of connecting members 225. As is clear from FIG. 4, the end panels 216 include a substantial number more connecting members than the intermediate panels, and in the illustrated embodiment, the intermediate panels have five connecting members, while the end panels have ten connecting members. Because of the greater number of connecting members in the end panels, an effective wall of water is provided at each end of the boiler which provides a degree of cooling at each boiler end.

The water entering the vertical riser portions 19, 119 and 219 flows into the respective connecting members 25, 125 and 225 through the openings 21, and then outwardly through the openings 21 into the vertically extending hot water outlet header portions 20, 120 and 220. The water is heated and evaporated in the connecting members 25, and 225, and because of the inclination of central portions 25c, 125c and 2250, the heated, less dense water and steam flows freely upwardly into the outlet headers and into the steam drum 18. The outlet headers 20, 120 and 220 are larger in diameter than inlet headers 19, 119 and 219 to accommodate the steam. One or more steam outlets 18 is provided in the steam drum 18.

Downcomer means, in the form of vertical tubular members 31, communicates with opposite ends of the steam drum 18 and with the ends of water inlet drum 17. Condensed steam is circulated from the drum 18 through the downcomer tubes 31 to the inlet drum 17, from whence it again passes upwardly through the riser panels 16, 116 and 216. The condensed steam in downcomers 31 is denser than the water being heated in the riser connecting portions 25, 125 and 225, so that a differential pressure head is established to create natural circulation of the water through the boiler. It should be understood, of course, that pump means may be provided to create forced circulation, if desired. An inlet tube 32 communicates with water inlet drum 17 to provide make up water. As is clear from FIGS. 2 and 3, the downcomer members 31 are spaced outwardly of the end riser panels 216, so that the downcomer members are clearly spaced from the heating area of the boiler. In this connection, it should be noted that the outermost of the burner nozzles 28 are spaced inwardly of the end panels 216, so that the end panels 216 provide a degree of insulation for the downcomers 31. Additional insulation is provided by refractory material outwardly of the end panels 216, to be hereafter described.

As may be best seen in FIGS. 2, 3 and 6', refractory members 33 are bonded between the vertically extending header portions 19, 119 and 219 of the riser panels. The refactory is formed of a suitable firebrick material, which is somewhat T-shaped in cross section, as can be best seen in FIG. 6. The members 33 include a generally planar outer face 33a, and arcuate side faces 33b positioned against the adjacent surfaces of the headers 19, 119 and 219. Refractory members 33 can be conveniently carried by metal flanges 34 at the lower portion of side walls 13, and the refractory material preferably extends upwardly to the lower ends 24 and 124 of the outlet headers 20 and 120, respectively. Additional refractory material 35, preferably in the form of a slidable panel, is provided outwardly of the endmost panels 216, inwardly of the downcomers 31, so that the heat of combustion is effectively retained within the combustion chamber C. As can be best seen in FIG. 4, side walls 13 are formed of two spaced sheet metal members 36 and 37, and an insulating material 38 is provided between members 36 and 37 to prevent the housing walls 13 from being heated to any appreciable amount. Side Walls 13 are also preferably supported on flange 34 outwardly of refractory members 33.

Baflle means are provided at the upper portion of the housing 11 for directing the flue gases outwardly of line openings F in the top of the housing 11. As is best seen in FIG. 4, upwandly inclined surfaces 40 extend inwardly from the upper ends of side walls 13, and downwardly inclined portions 44 extend inwardly from the lower portion of the upper side wall portions 134. Upwardly inclined portions 45 extend inwardly from the lower end of portions 44 in general parallelism with portions 40, to define a longitudinally extending opening 46 therebetween. Upwardly inclined portions 40 terminate at 40a, to define openings 43 which establish communication between the interior of the housing 11 and the atmosphere. Further inclined portions 41 extend upwardly and inwardly from the end portions 40a of inclined portions 40, and inclined portions 41 are positioned beneath flue opening F, with vertical panels 42 being provided at opposite sides of the members 41. Thus, the flue gases are free to pass upwardly around inclined portions 40 at the sides of members 41, and then upwardly between members 42 outwardly of the flue opening F into a suitable stack, not shown. If a downdraft occurs, the baflle means provided by the inclined members 41 will prevent the downdraft from extinguishing the gas flame provided by nozzles 28, and the flue gases will pass outwardly of the housing through the openings 46.

From the foregoing it is believed clear that each of the objects of the invention have been fully achieved. Although the boiler structure disclosed above has been described in terms of a steam generating boiler, it will be readily apparent to those skilled in the art that the same general structure will function equally well for a hot water boiler. When used as a hot water boiler, a smaller upper drum 18 may be utilized, and in preferred embodiments, when used as a steam generating boiler the drum 18 is 20" in diameter, while when used as a hot water generating boiler, the upper drum 18 is 12" in diameter. In each of the embodiments mentioned above, the lower drum 17 is approximately 6" in diameter, while the inlet header tubes and connecting member tubes are 2" in diameter and the outlet header tubes are 2 /2 in diameter. The inlet and outlet headers are preferably spaced apart approximately 28" in each of the embodiments mentioned above, and the lowermost connecting members are spaced approximately 17%" above the nozzles 28, so that the combustion chamber 0 is rectangularly shaped in cross section, having dimensions of 17%" by 28.

We claim:

1. A panel for use in a boiler comprising; a vertical inlet header; a plurality of vertically spaced outlet openings in said inlet header; a vertical outlet header; a plurality of vertically spaced inlet openings in said outlet header, each outlet header inlet opening corresponding to one inlet header outlet opening and being spaced vertically thereabove; and a tubular connecting member extending between each inlet header outlet opening and each outlet header inlet opening, each connecting member having a generally horizontally disposed portion at one end communicating with its respective inlet header outlet opening, an intermediate portion inclined upwardly from said end portion toward the outlet header inlet opening, and a generally horizontally disposed portion at the opposite end communicating with its respective outlet header inlet opening.

2. A panel as set forth in claim 1 wherein said inlet header includes a generally laterally extending lower inlet end directed toward said outlet header, and said outlet header includes a generally laterally extending upper outlet end directed towards said inlet header.

3. A panel as set forth in claim 1 wherein said outlet header is larger than said inlet header.

4. A panel as set forth in claim 1 wherein an outwardly extending peripheral flange is provided around each of the inlet and outlet openings in alignment with and secured to the adjacent end of the respective connecting member.

5. A panel as set forth in claim 4 wherein a back up ring extends partially into each header flange and into the adjacent connecting member end, so as to be positioned under the connection between the connecting memher and flange.

6. A boiler comprising: a housing; a water inlet drum at the lower portion of said housing; a hot water-steam outlet drum at the upper portion of said housing; a plurality of adjacent, longitudinally spaced heat exchange panels in said housing, each panel including a vertical inlet header having a lower portion communicating with said water inlet drum, a vertical outlet header having an upper portion communicating with said hot water-steam outlet drum, and a plurality of vertically spaced connecting members inclined upwardly between said inlet header and said outlet header to define an expanded heat exchange area, the outermost of said panels including more connecting members than the panels therebetween to provide water cooling at the ends of the boiler; downcomer means connected between said hot water outlet drum and said water inlet drum for recirculating Water to said panels; and means within said housing for heating said panels.

7. A boiler as set forth in claim 6 wherein said downcomer means is spaced from said heat exchange panels.

8. A boiler as set forth in claim 6 in which the lower portion of each inlet header is generally horizontally disposed, and wherein said heating means is positioned above said inlet header lower portions, whereby water cooling is provided at the bottom of the boiler.

9. A boiler as set forth in claim 6 wherein the inlet header of each panel is positioned on one side of said drums and the outlet header of each panel is positioned on the opposite side of said drums, so that said inlet header lower portions communicate with said water inlet drum at said one side thereof and said outlet header upper portions communicate with said hot water-steam Outlet drum at said opposite side thereof.

10. A boiler as set forth in claim 9 wherein adjacent panels are reversed throughout the length of said boiler, so that the communicating portions of adjacent panel headers engage opposite sides of said drums and the connecting members of adjacent panels are oppositely inclined, whereby a tortuous path is defined for heating gases emanating from said heating means.

11. A boiler as defined in claim 6 wherein said heating means includes a plurality of heating elements spaced longitudinally and transversely throughout said boiler.

12. A boiler comprising: a housing; a water inlet drum at the lower portion of said housing; a hot water-steam outlet drum at the upper portion of said housing; a plurality of adjacent, longitudinally spaced heat exchange panels in said housing, each panel having hot water riser means communicating with the Water inlet drum and with the hot watensteam outlet drum, and each panel having means providing an expanded heat exchange area; downcomer means connected between said hot water outlet drum and said water inlet drum for recirculating water to said panels; means within said housing for heating said panels; said housing including insulated side and end walls enclosing said drums, panels, and heating means therewithin, said housing having a gas outlet opening in the top thereof with baflle means in the upper portion of the housing for directing gases from said heating means 8: passing upwardly through said panels to said opening, said battle means including means communicating with the atmosphere and means for preventing extinguishing of said heating means.

References Cited UNITED STATES PATENTS 813,245 2/1906 Sneddon 122365 1,503,614 8/1924 Travers l22255 1,798,550 3/1931 McKnight et al. 122-253 2,186,860 1/1940 Evans 122328 3,299,859 1/1967 Dalin 122-328 FOREIGN PATENTS 634,750 3/1950 Great Britain.

KENNETH W. SPRAGUE, Primary Examiner.

UNITED STATES PATENT OFFICE Patent No.

Inventor(s) Dated JOHN C. CLEAVER et al June 4, 1968 It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

which reads "Cleaner-Brooks Company" --Aqua-Chem,

(SEAL) Anew Edward M. Fletcher, Jr. Atte tiug Officer SIGNED AND SEALED NOV 2 51969 should read WILLIAM E. SQHUYLER, JR. Commissioner of Patents 

